Which do I need- Bow lift or stern lift prop?
#11
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From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Trust me I have tried them all!!!!!! and painfully recorded all of the data every single time with my old MIdnight.
And keep in mind you have deep-veeeeee hull. Rough water boat. Your speed is going to be slower than the newer hulls with step, pads etc....but u will be glad when you are in the rough stuff. So when your testing make sure yuo use the same water conditions .as you will notice an increase in speed when it becomes choppy...natural ventilation!!!
REV 4 gave best all around performance, Mirage Plus best Top end but worst cruise speed and would break loose.
B-1 was a very close second to Rev 4 but I needed more stern lift due to the triple engine weight on stern.
Of course your application is different. Sounds like your x-dimensions is probably higher than stock which would reduce the affects of a bow lifting prop which of course would lessen any bow lifting characterics of the Bravo 1.
Brett is the man though.........keep working with him he will figure it out.
Last edited by Enforcer2; 08-03-2008 at 10:07 AM.
#13
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From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Gotcha, just a facto to consider.....this will definetly make a difference in what type of prop u should be running.
Look at the relationship to your boat bottom........single engine right beneath the outdrive.
Take a stright edge and run it from the boat bottom to your outdrive and see where it ends up.
If the cavitation plate is even or close to even with the bottom thats pretty normal. If your water intakes are closer to the bottom its probably raised.
here's an example of a raised "transom height -outboard term........for you stern drives x-dimension) This is extrme -low ater pick ups and more of a surface prop like the B-1
P.S 3 blades generally speaking are always faster on DEP VEE 24 degree huals like u and I have.
Look at the relationship to your boat bottom........single engine right beneath the outdrive.
Take a stright edge and run it from the boat bottom to your outdrive and see where it ends up.
If the cavitation plate is even or close to even with the bottom thats pretty normal. If your water intakes are closer to the bottom its probably raised.
here's an example of a raised "transom height -outboard term........for you stern drives x-dimension) This is extrme -low ater pick ups and more of a surface prop like the B-1
P.S 3 blades generally speaking are always faster on DEP VEE 24 degree huals like u and I have.
#14
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From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Here's a 24 Baja w/single engine for comparison this is pretty standard.
The red line is just under the cavitation plate and the purple line is the nose of the lower
The red line is just under the cavitation plate and the purple line is the nose of the lower
#15
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From: Wayland, MI
I'm going to measure that again and post. (I did it before but can't remember what it was) I have tried a 1" spacer and it slowed the boat down 3MPH or so. So that is the wrong direction to go.
#16
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From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Ok....I would still try to stay with either a Mirage plus 3 blade...which would require a lot less trim so it may not blow out at all. Again 24 degree deep v hull different animal 3 blades are the fastest on these hulls
You will see a top end number increase but will definelty also loose in your cruising speed ( I gained about 6 mph at same rpm with cruising speed when I switched from Mirage plus to B-1 but I lost 3 mph on top)
Working with Brett he introduced me to the Rev 4 .....Mercs cross between the mirage plus and the Bravo 1.
I can't imagine your x-dimension is toohigh just good to know if it has been modified.
Let me know if can help
Tony
You will see a top end number increase but will definelty also loose in your cruising speed ( I gained about 6 mph at same rpm with cruising speed when I switched from Mirage plus to B-1 but I lost 3 mph on top)
Working with Brett he introduced me to the Rev 4 .....Mercs cross between the mirage plus and the Bravo 1.
I can't imagine your x-dimension is toohigh just good to know if it has been modified.
Let me know if can help
Tony
#17
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Joined: Nov 2005
Posts: 387
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From: Wayland, MI
Gotcha, just a facto to consider.....this will definetly make a difference in what type of prop u should be running.
Look at the relationship to your boat bottom........single engine right beneath the outdrive.
Take a stright edge and run it from the boat bottom to your outdrive and see where it ends up.
If the cavitation plate is even or close to even with the bottom thats pretty normal. If your water intakes are closer to the bottom its probably raised.
here's an example of a raised "transom height -outboard term........for you stern drives x-dimension) This is extrme -low ater pick ups and more of a surface prop like the B-1
P.S 3 blades generally speaking are always faster on DEP VEE 24 degree huals like u and I have.
Look at the relationship to your boat bottom........single engine right beneath the outdrive.
Take a stright edge and run it from the boat bottom to your outdrive and see where it ends up.
If the cavitation plate is even or close to even with the bottom thats pretty normal. If your water intakes are closer to the bottom its probably raised.
here's an example of a raised "transom height -outboard term........for you stern drives x-dimension) This is extrme -low ater pick ups and more of a surface prop like the B-1
P.S 3 blades generally speaking are always faster on DEP VEE 24 degree huals like u and I have.
Last edited by Old Navy; 08-03-2008 at 11:26 AM. Reason: sic
#19
I agree, with a propshaft that deep a Mirage + or Rev 4 should work well and provide excellent bow lift. I LOVE the handling of my Rev4.
#20
The best prop for you is probably going to a re worked/labbed Bravo 1. Get some added cup and rake. Your 283 is somewhat comparable to my 28 Pantera. I had a 525Sc as well and needed bow lift. I was only at 4.25 propshaft depth though. Its just a big boat for a single engine and hard to lift the bow. I don't think a Mirage Plus will get on plane worth a darn or have any kind of cruise speed. It might be the best on top end, but I'm sure BBlades could get you there with a good lab job on Bravo 1 as well.




